AutoCodes – Jeep – P0307 Jeep

P0307 Jeep Code - Cylinder 7 Misfire Detected

Quick Answer

The Engine Control Module (ECM) uses information from the crankshaft position sensor and the camshaft position sensor to determine when an engine cylinder misfire is occurring. Common causes include Faulty spark plug 7, Clogged or faulty fuel injector 7, Faulty ignition coil 7. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0307 Jeep indicates Cylinder 7 Misfire Detected.
Common causes: Common causes include Faulty spark plug 7, Clogged or faulty fuel injector 7, Faulty ignition coil 7.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 2,383

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 09, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0307 Jeep Description

The Engine Control Module (ECM) uses information from the crankshaft position sensor and the camshaft position sensor to determine when an engine cylinder misfire is occurring. By monitoring variations in the crankshaft rotation speed for each cylinder, the ECM can detect individual cylinder misfire events.
Extreme cylinder misfire events can cause catalytic converter damage. The malfunction indicator lamp (MIL) will flash when the conditions for catalytic converter damage are present. The Diagnostic Trouble Codes (DTC) P0307 correspond to cylinders 7. When the ECM detects that one or more specific cylinders are misfiring, the DTC for the respective misfiring cylinder will set, and up to 2 of the corresponding fuel injectors are disabled for a minimum of 30 s. The ECM will then re-enable the fuel injector and, after approximately 200 engine revolutions, will determine if the misfire is still present. If the misfire is still present, the ECM will disable the fuel injector again repeating the process. If the misfire is not present, the fuel injector will remain enabled by the ECM. In Spark Ignition Direct Injection (SIDI) system applications, if a fuel injector fault DTC is set during a misfire event, the ECM will not re-enable the injector.

OBDII Code P0307 Jeep - Cylinder 7 Misfire Detected - AutoCodes.com — P0307 Jeep Code - Cylinder 7 Misfire Detected

What does this mean?

What are the Possible Causes of the DTC P0307 Jeep?

Faulty spark plug 7
Clogged or faulty fuel injector 7
Faulty ignition coil 7
Fuel injector 7 harness is open or shorted
Fuel injector 7 circuit poor electrical connection
Ignition coil 7 harness is open or shorted
Ignition coil 7 circuit poor electrical connection
Insufficient cylinder 7 compression
Incorrect fuel pressure
Intake air leak

How to Fix the DTC P0307 Jeep?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

The P0307 code means that cylinder 7 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 7. If the problem persists more tests need to be done to diagnose the problem, see "Possible Causes".

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0307 Jeep code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0307 Jeep Code

1. What are the common symptoms of an OBDII code P0307 in a Jeep indicating a Cylinder 7 misfire?

The common symptoms include rough idle, lack of power, engine vibration, and potentially increased fuel consumption.

2. What are the typical causes of a Cylinder 7 misfire detected in a Jeep triggering the OBDII code P0307?

Possible causes include faulty spark plugs, ignition coil issues, fuel delivery problems, vacuum leaks, or a malfunctioning fuel injector specific to Cylinder 7.

3. How can I diagnose the source of a Cylinder 7 misfire in my Jeep when the OBDII code P0307 appears?

You can diagnose the issue by inspecting spark plugs, ignition coils, fuel injector for Cylinder 7, checking for vacuum leaks, and performing a compression test on Cylinder 7.

4. Are there any tips for repairing a Cylinder 7 misfire in a Jeep related to the OBDII code P0307?

Consider replacing spark plugs, ignition coils, or the fuel injector for Cylinder 7 if found faulty. Additionally, ensure proper fuel delivery and address any vacuum leaks.

5. Can driving with an OBDII code P0307 indicating a Cylinder 7 misfire in a Jeep cause further damage?

Continued driving with a misfire can lead to damage to the catalytic converter due to unburned fuel reaching it. It is recommended to address the issue promptly.

6. Is it possible to reset the OBDII code P0307 related to a Cylinder 7 misfire in a Jeep without performing any repairs?

Resetting the code without addressing the underlying issue may temporarily remove the warning light, but the problem will likely reoccur until the root cause is fixed.

7. How can I prevent a Cylinder 7 misfire in my Jeep triggering the OBDII code P0307 in the future?

Regular maintenance, such as changing spark plugs and inspecting ignition components, can help prevent misfires. Ensuring timely repairs of any detected issues is also crucial.

8. Are there any specific models of Jeep known to be more prone to Cylinder 7 misfires triggering the OBDII code P0307?

While any Jeep model can experience Cylinder 7 misfires, certain models with higher mileage or older components may be more susceptible. Regular maintenance is key to prevention.

9. Can extreme weather conditions or altitude affect the likelihood of a Cylinder 7 misfire in a Jeep leading to the OBDII code P0307?

Extreme weather conditions or high altitudes can impact engine performance and potentially lead to misfires. Ensuring proper engine tuning and maintenance can help mitigate these issues.

10. Should I be concerned about safety when driving with an OBDII code P0307 signaling a Cylinder 7 misfire in my Jeep?

Driving with a misfire can affect vehicle performance and fuel efficiency. While it may not pose an immediate safety risk, addressing the issue promptly is recommended to prevent further damage.